15 scary and awesome viewing platforms

(CNN) — Think you can handle a 340-meter-high, open-air glass walkway? How about one with no guard rail?

Shanghai Skywalk is among the latest daredevil challenges for fear-free travelers. It joins an adrenaline-inducing roll call of destinations around the world offering spectacular views:

1. Shanghai Skywalk (China)

"In 24 Hours" host James Williams tries out the new glass walkway around the 88-story Jin Mao Tower. There are no fences or rails -- just a safety harness

At the 88-story Jin Mao Tower in Shanghai, visitors will be able to walk around a new glass walkway on the outside of the building, 340 meters above the city. The 1.2-meter-wide platform has no fence and no guard rails; only a safety harness stands between you and oblivion.

Tickets aren't yet on general sale -- and there's no confirmation when they will be -- but when CNN visited Shanghai for travel series "In 24 Hours," host James Williams just had to try it out.

2. Brighton i360 (United Kingdom)

The i360 cost $55.9 million to build.

British Airways i360/Visual Air

The world's tallest moving observation tower, the 162-meter British Airways i360, opened in Brighton, England, in August 2016. It's also the world's slimmest, with a height to width ration of more than 40:1. Visitors glide to the top in a futuristic glass-and-steel pod, enjoying 360-degree views over the seaside town and the English Channel. It was designed by London firm Marks Barfield Architects, the same team behind the London Eye.

3. SkySlide at Skyspace LA (United States)

Visitors to the U.S. Bank Tower in Los Angeles can take a SkySlide to slide from the 70th to the 69th floor of the tallest building west of Chicago.

Since June 2016, visitors to the new OUE SkySpace LA observation deck atop the US Bank Tower in Los Angeles have been able to coast down the SkySlide, a glass chute affixed to the outside of the building, going from the 70th floor to the 69th. The 45-foot-long, 1.25-inch-thick tube hovers 1,000 feet above the sidewalks below. The glass is made to withstand hurricane-force winds of up to 110 miles per hour and is held together by steel outriggers.

4. Dachstein Stairway to Nothingness (Austria)

Visitors to Dachstein's Stairway to Nothingness must first cross Austria's highest bridge, the 100-meter-long Dachstein suspension bridge which straddles a drop of 396 meters. They then face 14 steps that descend from the cliff face and which are surrounded by glass walls.

The entire structure took six months to build and was created by an engineering firm specializing in high-altitude construction. And if you've not had enough of incredible sights, the nearby glass-bottomed Dachstein Glacier Skywalk offers views as far as the Triglav mountains of Slovenia and the forests of the Czech Republic.

5. Tokyo Skytree observation decks (Japan)

The Tokyo Skytree is Japan's tallest structure, with a height of 2,080 feet (634 meters). It has two observation decks. The lower one is located at 1,148 feet (350 meters) and has a section of glass flooring.

The upper one, which has floor-to-ceiling windows and 360-degree-views of the city, has a height of 1,476 feet (450 meters). On a clear day, Mount Fuji can be seen from the observation decks.

6. Kinzua Skywalk (United States)

The best way to recycle a viaduct.

courtesy kinzua skywalk

When the Kinzua Viaduct was built in Pennsylvania in 1882, it was the longest and highest viaduct in the world. In 1900 it was rebuilt to carry heavier trains, using 3,175 tons of steel and 895,000 rivets.

In 2003, a tornado destroyed 11 of the 20 towers and it was decided that the remaining towers would be used to support the Skywalk. The Skywalk extends 624 feet (190 meters) into the Kinzua Gorge and glass panels allow visitors to peer into the gorge below.

7. AlpspiX viewing platform (Germany)

At the base of Germany's Alpspitze mountain, the AlpspiX viewing platform comprises two steel beams, both of which measure 79 feet (24 meters) in length. Visitors brave enough to walk to the end of the glass-walled platforms can look 3,281 feet (1,000 meters) down into the valley. The platform remains open in winter, when the grid flooring allows snow and ice to pass through.

8. EdgeWalk CN Tower (Canada)

Located on the roof of the CN Tower's restaurant at a height of 1,168 feet (356 meters), the EdgeWalk allows visitors to slip into climbing harnesses and walk around the edge of Canada's tallest structure. There's also a glass floor 1,122 feet (342 meters) above ground level, and although the glass is only 2.5 inches thick, it's reportedly strong enough to hold 14 hippos -- if they could fit in the elevator.

The EdgeWalk holds the world record for world's highest external walk attached to a building. CN Tower also has a glass-floored observation deck and outdoor SkyTerrace.

9. The Ledge (United States)

The Ledge: One of the world's highest wedding venues.

courtesy skydeck willis tower

The four boxes that make up The Ledge experience in Willis Tower, Chicago, are made from half-ton panels of glass. The walls consist of three layers, each half an inch thick. Visitors who step into one of the boxes can see for 50 miles across four states, as well as 1,353 feet (412 meters) to the street below.

It's a popular site for wedding proposals -- as if popping the question wasn't scary enough -- and visitors can even get married in them. The boxes retract into the building when the windows need cleaning.

10. Cliffwalk (Canada)

The Cliffwalk is a 700-feet (213 meter) walkway attached to a granite cliff face above the Capilano River in British Columbia, Canada. The highest point is 300 feet (90 meters) above the river.

To attach the Cliffwalk, 16 anchor points were drilled 19 feet (six meters) into the rock face using 1,825 bolts, and 40 tons of steel were used. The Cliffwalk also features two glass panels that have an anti-skid finish and were shipped over from Austria.

11. The View from The Shard (England)

London's The Shard is the tallest building in Western Europe and The View From The Shard is located on floors 68, 69 and 72. The best panoramas are from floor 72, at a height of 800 feet (244 meters). This open-air observation deck offers 360-degree views of the city. Visitors can also look up into the "shards" of glass that form the top of the skyscraper.

12. Stegastein lookout (Norway)

The platform's almost as beautiful as the view.

courtesy nils vik

The glass panel at the end of this walkway gives visitors the impression they could simply fall off the end. Commissioned by the Norwegian Highway Department as part of a project to improve the appearance of the country's tourist routes, the lookout allows visitors to look straight down into the Aurlandsfjord, 2,000 feet (609 meters) below.

Stegastein lookout, Aurland-Laerdal Road, Aurland, Norway; +47 57 631400; admission is free, but the easiest way to access it is by a sightseeing tour from Flam ($34)

13. Top of Tyrol Stubai Glacier (Austria)

The Top of Tyrol viewing platform in Austria was completed in 2008 and provides visitors with spectacular views over 103 peaks. All of the parts -- including 19 tons of steel and a 164-foot (50-meter) hand rail were lowered into place by helicopter. It's 10,433 feet (3,180 meters) above sea level and 50-foot (15-meter) rock anchors keep the structure in place.

14. Matteo Thun's Viewing Platform (Italy)

Spectacular views of Italy's most beautiful gardens.

courtesy sudtirolmarketing

The best views of Italy's Merano region are from this binocular-shaped viewing platform, high above the gardens' huge oak forest. The viewing platform is just one of several within the gardens, which in 2005 were named Italy's most beautiful gardens. The platform is suspended over the Gardens of Trauttmansdorff and was designed by architect Matteo Thun.

15. Grand Canyon Skywalk (United States)

This steel and glass, horseshoe-shaped walkway extends 70 feet (21 meters) over the lip of the Grand Canyon, almost one mile above the valley floor. The 90 tons of glass were imported from Germany. The Skywalk, which is bolted to the canyon's rim, can support the weight of 70 747 passenger jets. Apollo astronaut and the second person to set foot on the Moon, Buzz Aldrin was the first person to step onto the Skywalk, which cost $30 million to build.